1. Field
This invention relates to apparatus adapted for extending and retracting a fabric cover over a contained body of water, such as a swimming pool.
2. Statement of the Art
Swimming pools of both the residential and commercial variety are becoming commonplace in contemporary society. With increasing demands being place on supplies of natural resources such as water and energy, serious attention is now being directed to more conservationist approaches in managing swimming pools. Observably, swimming pools can be a source of considerable water loss due to evaporation. Secondly, the cost of the energy required to maintain the temperature of the water in the pool at a level comfortable for swimming is a strong incentive to adopt measures which promote retention of heat in the pool and retain heat loss.
As a tertiary consideration, it should be remembered that conventional swimming pool maintenance requires the frequent treatment of the water in the pool with antibacterial preparations such as chlorine. Loss of these preparations due to evaporation can create a sizable financial burden to the pool owner.
Within the last forty years, innovative attempts have been made to develop covers which could be placed over the swimming pool during times of nonuse. These covers address many of the problems raised above. The covers tend to retard evaporation of the water and antibacterial preparations from the pool. Secondly the covers retain heat within the pool water. Some cover manufacturers have even advocated that their covers act as solar collectors in that the sun's rays are permitted to continue heating the water with the cover in place. The cover then retains the heat within the water, thereby leading to an increased overall heat gain.
Conventional swimming pool covers typically include a pair of rigid guide tracks which are installed along parallel opposite sides of the pool. A cover collecting drum is disposed adjacent one end of the pool. A fabric cover often manufactured of a heavy weight vinyl is wrapped about the drum. The sides of the fabric cover are generally formed to have a beaded edge which is configured to be received into a respective guide track for back and forth guided displacement along the guide track. Conventionally, each beaded edge is formed by the cover being hemmed along its side edge. A respective rope is passed through each hem to form a bead. The rope exits the hem at the end of the cover. The rope is directed into a separate channel in the guide track which leads the rope back to a rope-collection reel positioned proximate the cover collecting drum. The cover is displaced along the guide track by a drive assembly which includes a motor, a drive shaft connected to the motor, and a plurality of rope collecting reels.
A plurality of reels is mounted on the drive shaft and is thereby operably associated with the motor. The drive shaft is also connected to the cover collecting drum.
Operationally, the motor, in one condition, is adapted to collect the ropes on their respective reels by rotating the reels. In this condition the cover collecting drum is traditionally rendered free wheeling about the drive shaft. As the ropes are collected on the reels, the cover is forcedly extended across the pool as the ropes are displaced through their respective guide tracks on their way to be collected on their respective reels. To retract the cover, the motor is shifted to a second condition wherein the cover collecting drum is directly engaged with the motor. Correspondingly, the reels are now left in a free wheeling condition about the drive shaft. As the cover collecting drum is turned, the cover is forcedly wrapped about the drum thereby retracting the cover from off of the pool.
While residential pools have been well served by conventional pool cover systems, serious complications have been encountered when attempts have been made to apply conventional pool cover systems to large commercial swimming pools. Oftentimes, commercial pools are so wide dimensionally that the weight of a vinyl cover, which would be required to span the pool exceeds any practical weight carrying limitations of a guide track which could be used to guide it. In recognition of this problem, current attempts to cover commercial pools have been directed to the use of multiple panels of a fabric formed of a polyethylene substrate adhered to a foam buoyant layer. The fabric is formed into elongate panels which are manually pulled over the surface of the water in the pool. The panels are then floated into engagement one with another to form a floating cover system.
While conventional systems require the user to manually pull the cover over the pool, some efforts have been made to devise a manually operated roller adapted to retract the cover from the pool once it has been installed. Another system utilizes a driven cover collecting drum which is mounted to an upstanding wall adjacent the end of the pool. The drum is fitted with a plurality of straps mounted spacedly along the length of the drum. The straps are each secured to the cover at spaced locations along the cover end. The cover is installed over the pool by the user manually pulling the cover off of the cover collecting driver and manually positioning the cover over the pool. When it is desired to retract the cover from the pool, the drum is rotated by a motor. The rotation of the drum causes the cover to be collected on the drum thereby retracting it from off of the pool.
While these systems somewhat address the problem of powered retraction of the cover from a commercial pool, these systems do not provide a mechanism for powered extension of the cover over the pool. There continues to be a need for an apparatus adapted to both extend and retract a cover over a commercial or large residential swimming pool.